p11 Protein Levels in Patients With Major Depressive Disorder Treated With Citalopram

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Complementary work will continue at other laboratories to better characterize the role of p11 in the pathophysiology of depression (e.g., animal studies, post-mortem studies). [ Time Frame: Baseline, +1 week, +2 weeks, +8 weeks ]

Original Secondary Outcome Measures

Not Provided

Current Other Outcome Measures

Not Provided

Original Other Outcome Measures

Not Provided

Descriptive Information

Brief Title

p11 Protein Levels in Patients With Major Depressive Disorder Treated With Citalopram

Official Title

An Investigation to Determine Whether Levels of P11 Protein in Peripheral Blood Cells Correlate With Treatment Response to Citalopram in Patients With Major Depressive Disorder

Brief Summary

This study will compare levels of p11 protein in people with and without major depressive disorder (MDD) and examine if p11 levels in patients are affected by treatment with citalopram (Celexa).

Healthy normal volunteers and patients with chronic or recurrent major depression between 18 and 65 years of age may be eligible for this study.

Participants undergo the following tests and procedures:

Healthy Volunteers

Psychiatric interview and medical examination, questions about family history

Blood draw

Patients with MDD

Phase 1 - Evaluation and Discontinuation of Medications

Physical examination, electrocardiogram, blood tests

Gradual antidepressant medication withdrawal, followed by 2- to 6-week drug-free period. If needed, medicines for anxiety and difficulty sleeping may be prescribed.

Phase 2 Citalopram Treatment

Start daily citalopram treatment

Evaluations at the start of phase 2 and every week for 8 weeks with following procedures:

Symptoms ratings interview and questionnaires

Review of side effects and new medications

Blood pressure and pulse measurements

Blood and urine tests

At the end of the study, plans are developed for long-term treatment and transfer of care to the patient s own physician.

Detailed Description

Major depressive disorder (MDD) is a serious, debilitating, life-shortening illness that affects many persons of all ages and backgrounds. While treatments are effective for a significant portion of patients with MDD, progress in developing more effective treatments is lagging. Furthermore, with regards to existing antidepressant medications, there are yet no reliable predictors of the likelihood of remission, response or non-response with an initial trial of an antidepressant medication. Identifying factors that are likely to predict response would have the advantage of personalizing treatment to a particular individual; that is selecting the antidepressant medication that is most likely to give the greatest probability of having a favorable outcome.

The serotonin system has been implicated in the pathophysiology of depression and mechanism of action of existing effective antidepressant treatments. Fourteen different serotonin receptors have been identified to date. One of them, 5-HT1B, plays an important role in regulating serotonin neurotransmission. Recently, p11 (a member of the S100 family of proteins) was found to interact with 5-HT1B receptors (Svenningsson et al 2006; Svenningsson and Greengard 2007). p11 mRNA levels are markedly reduced in the forebrain in helpless H/Rouen mice and the level of p11 mRNA was down-regulated in the anterior cingulate cortex from depressed patients. p11 mRNA is distributed in an anatomical pattern that closely resembled that of 5-HT1B receptor mRNA, including cortex, hippocampus, hypothalamus and raphe nuclei. Chronic administration of the antidepressants imipramine, tranylcypromine, and citalopram significantly increase the level of p11 in cortex. Finally, we have found that chronic treatment with fluoxetine increases p11 in peripheral mononuclear cells in monkeys.

We will now study whether the blood cell levels of p11 differ between healthy individuals and patients suffering from unipolar depression. Moreover, we will study whether the levels of p11 are affected by treatment with the selective serotonin reuptake inhibitor, citalopram. Complementary work will continue at other laboratories to better characterize the role of p11 in the pathophysiology of depression (e.g., animal studies, post-mortem studies).

In addition, we will also acquire a battery of magnetic resonance imaging (MRI) scans in a subset of 45 more homogeneous depressed subjects, and 45 matched healthy controls at baseline and at 8 weeks. There is a growing body of evidence implicating morphometric and physiologic abnormalities, measureable by MRI, in the pathophysiology of major depressive disorder. We will assess both baseline differences between depressed subjects and healthy controls, treatment effects, and search for possible MRI markers predicting treatment response.

This is an open label study which will be performed at the National Institute of Mental Health. In all, 82 adult subjects with major depressive disorder, between the ages of 18 and 65 years, will be recruited from the community. In addition, we will perform p11 measurements in blood cells from 64 healthy control subjects.

has general medical condition which contraindicates the use of the study medication

is on concomitant medication which contraindicates the use of the study medication

requires immediate hospitalization for psychiatric disorder

requires antipsychotic medications or mood stabilizers

Non-postmenopausal (less than 2 years since last period) females of childbearing potential who are sexually active and who are not using adequate (hormonal, double barrier, surgical) contraception, or who are pregnant or breast feeding

patients currently taking any of the exclusionary medications detailed in protocol (including antipsychotic medications, anticonvulsant medications, antidepressant medications, mood stabilizers, central nervous system stimulants) in the 2 weeks prior to Study Period II.

patients taking thyroid medication for hypothyroidism may be included if they have been stable on the medication for greater than 3 months

patients can participate in a modality of psychotherapy that is not targeting the symptoms of depression (e.g., supportive therapy, marital therapy)

therapy that is depression specific, such as Cognitive Therapy (CT) or Interpersonal Psychotherapy of Depression (IPT) is not allowed during participation

subjects must be fluent in English and have the capacity to understand the nature of the study and sign the written informed consent.

current alcohol dependence or abuse (last 3 months)

patient has a prolonged QTc (greater than or equal to 450 msec), as shown on ECG

Current NIMH employee/staff or their immediate family member.

ADDITIONAL CRITERIA FOR EXCLUSION OF DEPRESSED PATIENTS FOR MRI IMAGING: